add 2019-01-21-agent-plugin-practice.md (#28)

* add 2019-01-21-agent-plugin-practice.md

* image resources into the repo
3 files changed
tree: 2c5a191aed68842cffda626b64ce98470870cdc5
  1. docs/
  2. .gitignore
  3. .travis.yml
  4. package-lock.json
  5. package.json
  6. README.md